EPIC Function Vignette

Guide to import and use the NASA DSCOVR: EPIC API

Step 1: Import the function script

In order to call the function, we must import the R script where the function is defined (“epic_wrapper.R”).

If you are in another directory, you must also add the file path where this script is located in addition to the file name.

Step 2: Call the “get_image_urls(type, date)” function

Once the script has been successfully imported, call the get_image_urls() function and pass the type of images you want to view and the date.

Type: If no type is provided the default will be ‘natural’. Other types include ‘enhanced’, ‘aerosol’, and ‘cloud’.

Date: If no date is provided the default date is the most recent date with available images. Format should be ‘YYYY-MM-DD’.

The function returns a list of urls to access the images on a browser.

images <- get_image_urls('natural', '2024-01-01')

This is the first item from the images list:

Here are examples of the other types of images

images_enhanced <- get_image_urls('enhanced', '2024-01-01')
images_aerosol <- get_image_urls('aerosol', '2024-01-01')
images_cloud <- get_image_urls('cloud', '2024-01-01')

Enhanced

Aerosol

Cloud

Step 3: Call the “plot_centroids(type, date)” function

We can get an idea of the scope of each image taken on a given day by plotting the centroids of each image in the set. Call the plot_centroids() function with the same parameters as before.

plot_centroids('natural', '2024-01-01')

Image epic_1b_20240101024318 is taken with a centroid over Australia:

Image epic_1b_20240101151935 is taken with a centroid over South America on the same day: